Audio feedback for implantable medical device instruments

ABSTRACT

A method and apparatus for interpreting and displaying the status and diagnostic data of, and/or programming an implantable medical device is disclosed. The apparatus includes a microprocessor with multiple executable programs; data entry means, such as a keyboard or light pen; a display means such as a screen display and/or a printer; and may include a receiver and transmitter means for remote programming and interrogation of the implantable medical device. The apparatus further includes a stored audio signal to represent the status and diagnostic values of the implantable medical device.

FIELD OF THE INVENTION

The invention relates generally to the field of programmable biomedicalimplantable devices and more particularly to audio feedback in externalequipment such as programmers and analyzers used in conjunction withcardiac pacemakers, neurostimulators and the like.

BACKGROUND OF THE INVENTION

A wide variety of cardiac pacemakers are known and commerciallyavailable. Pacemakers are generally characterized by which chambers ofthe heart they are capable of sensing, the chambers to which theydeliver pacing stimuli, and their responses, if any, to sense intrinsicelectrical cardiac activity. Some pacemakers deliver pacing stimuli atfixed, regular intervals without regard to naturally occurring cardiacactivity. More commonly, however, pacemakers sense electrical cardiacactivity in one or both of the chambers of the heart, and inhibit ortrigger delivery of pacing stimuli to the heart based on the occurrenceand recognition of sensed intrinsic electrical events. A so called "VVI"pacemaker, for example, senses electrical cardiac activity in theventricle of the patient's heart, and delivers pacing stimuli to theventricle only in the absence of electrical signals indicative ofnatural ventricular contractions. A "DDD" pacemaker, on the other hand,senses electrical signals in both the atrium and ventricles of thepatient's heart, and delivers atrial pacing stimuli in the absence ofsignals indicative of natural atrial contractions, and ventricularpacing stimuli in the absence of signals indicative of naturalventricular contractions. The delivery of each pacing stimulus by a DDDpacemaker is synchronized with prior sensed or paced events.

Pacemakers are also known which respond to other types of physiologicalbased signals, such as signals from sensors for measuring the pressureinside the patient's ventricle or measuring the level of patient'sphysical activity. These labelled "VVIR" for a single chamber version or"DDDR" for a dual chamber version.

The complexity of modern pacemakers, the need to diagnose, optimize andadjust various parameters during the implant procedure, the occurrenceof rare device failures, or more commonly, physiologic changes, anddevice variables or drift, dictate the need for numerous programmableparameters accessible non-invasively via an externally operatedprogrammer. The need to assess system performance or troubleshoot thepatient, device and/or lead system in an acute, clinical settingrequires extensive telemetry capability in the implanted device andexternal programmer.

Modern programmers used to adjust the parameters of multi-functionimplantable medical devices, typically have graphic displays, keyboardsor light pens for data entry and device control by operatormanipulation, and printers or plotters to allow the user to easilycontrol, evaluate and document the extensive capabilities of modernmedical devices. An example of one such device is the Medtronic Model9760 programmer. Typically, in use during an implant procedure in thesurgical suite, the programmer is positioned outside the sterile fieldremote from the patient. A programming head, or wand containingtransmitter and receiver circuitry, is connected to the programmer via astretchable coiled cable, and positioned over the patient's pacemakerimplant site for programing or telemetry interrogation of the implanteddevice. The programmer typically consists of 1 or more microprocessorsand contains programmable memory capable of storing executable programsunder the control of the operator via keyboard or light per entry. Thephysician in the sterile field verbally communicates programmingdirections to a nurse or associate at the control of programmer outsideof the sterile field. The implanting physician often cannot see thescreen or display on the programmer because of the distance involved,small size of the screen, or display screen contrast limitations. Thisrequires the program operator to verbally communicate patient status,device function and status, and success or failure of requested programoperations to the physician.

Similarly, during an implant, a Pacing Systems Analyzer (PSA) istypically used to verify cardiac pulse generator function and evaluatelead pacing threshold and intrinsic signal amplitude values. Thesevalues are utilized to set the programmable parameters of theimplantable pulse generator to ensure an adequate safety margin forpacing and sensing, respectively. In use, the PSA is connected by testcables to the externalized proximal end of the lead system implanted inthe patient. The PSA is held and controlled by an assistant who reportsstimulation thresholds and R-wave/P-wave amplitudes on a beat-by-beatbasis. The PSA typically contains pacing and sensing circuitry, undercontrol of one or more microprocessors, and programmable memory capableof storing executable programs under the control of the operator viakeyboard entry. This process is error prone due to the potential errorsin the viewing of values on a small liquid crystal display (LCD) on atypical PSA and the verbal communication required to report to theattending physician.

In prior art, as the programmer operator enters strings of keystrokes tocontrol the operation of the programmer, to set up programmableparameter values for the implanted device or to program or interrogatethe implanted device, programmers have used an audio tone or "beep,"either intermittently or steady, to confirm programmer and/or implanteddevice function and status. Examples of prior art audio feedback includeU.S. Pat. No. 4,236,524 to R. Powell, et al., "Program TestingApparatus"; U.S. Pat. No. 4,250,884 to J. Hartlaub, et al., "ApparatusFor and Method of Programming the Minimum Energy Threshold For PacingPulses to be Applied to a Patient's Heart"; U.S. Pat. No. 4,305,397 toS. Weisbrod, et al., "Pacing Generator Programmer With TransmissionChecking Circuit"; and U.S. Pat. No. 4,323,074 to G. Nelms "PacemakerProgramming Apparatus Utilizing a Computer System with Simplified DataInput"; all assigned to the assignee of the present invention andincorporated herein in their entirety by reference. All operate, orsound, a beeper for valid keystroke entries. The '884 and '397 patentsalso describe sounding a beeper to indicate programmer status such as avalid downlink programming or the completion of a timeout function. The'074 patent also describes sounding a beeper to indicate a successfulbattery check operation upon device turn-on. Additionally, U.S. Pat. No.4,432,360 to U. Mumford, et al., "Interactive Programmer for BiomedicalImplantable Devices" describes intermittently sounding a beeper uponpower-up/self-test and at specific device function/status such asprogramming "STAT SET" or standard values. Additionally, a steady toneis sounded at the transmission of programming pulses and a pulsatingtone at the end of transmission or during self-test failure. With thepreviously listed needs and shortcomings of prior art programmers andanalyzers, the use of intermittent or steady tones is inadequate to meetcomplex present day requirements for patient safety and communication.

These and other problems are solved by the apparatus of this invention.

SUMMARY OF INVENTION

In accordance with this invention, there is provided audible spokenfeedback and data to the user of various instruments such as programmersand pacing systems analyzers for implantable medical devices such aspacemakers, defibrillators, neurostimulators and the like.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 shows a block diagram of one embodiment of the apparatus of theinvention.

FIG. 2 shows a further detailed block diagram of an embodiment of theinvention.

FIG. 3 shows a flow diagram of one embodiment of the invention.

DETAILED DESCRIPTION OF SPECIFIC EMBODIMENTS OF THE INVENTION

The present invention will now be more fully described with reference tothe various figures of the drawings. FIG. 1 shows generally how aprogrammer can, in accordance with the present invention, be used inconjunction with the patient 14. A pacemaker 16 implanted in the patient14 as is known in the art. Programming head 12 is connected via coiledcable 18 to programmer 10. It should also be understood that the presentinvention may be utilized in conjunction with other implantable medicaldevices, such as cardioverters, defibrillators, neurostimulators,cardiac assist systems, and the like.

Turning to FIG. 2, a block diagram of programmer 10 from FIG. 1 isshown. Although the present invention is described in conjunction withFIG. 2 having a microprocessor based architecture, it will be understoodthat it could be implemented in logic-based, custom integrated circuitarchitecture or any other method of implementation, if desired. In theembodiment shown in FIG. 2, programmer 10 is connected to display device102 which may be a cathode ray tube (CRT) display or liquid crystaldisplay (LCD). In addition, programmer head 12, containing transmittingand receiving circuitry, is connected to the programmer 10 viastretchable cable 18. Data entry devices, such as keyboard 126, mouse128, track ball 130, or light pen 132 may be manipulated by an operatorfor the entering of patient implant data and to control device functionand operation. A printer 116 is typically used for hard copy printout ofpatient implant or follow-up data, including programmable parametervalues, device and patient status and diagnostic data.

Microprocessor 108 in conjunction with RAM 118, ROM 122, and analogmemory 124 are used to control the function of the device via storedexecutable programs. RAM 118, ROM 122, and analog memory 124 areconnected to the microprocessor 108 via data bus 120. Printer 116 isconnected to and controlled via the printer control circuitry 114 whichis in turn connected to the microprocessor 108 via data bus 134. Display102, used for displaying device function/status and to show diagnosticdata, is connected to a display driver 104 which is in turn connected tothe microprocessor 108 via data bus 136. Speaker 110, used to announceor speak words or phrases, is driven by annunciator driver 106 which isconnected to, and controlled by, the microprocessor 108 via data bus138. Power supply 100 powers the programmer 10 in accordance with commonpractice in the art. Not shown, but an option, would be to replace thepower supply with rechargeable or primary cell batteries.

Analog memory 124 may be of the type incorporated in ISD 1016, atelecomunication monolithic integrated circuit from Information StorageDevices, Inc. Recorded voice data, or words, are stored in individualelectrically alterable read only memory (EEROM) locations in analogmemory 124. Analog memory 124 contains amplifier and filter functions toamplify and bandpass filter analog signals retrieved from memory.Additionally, analog memory 124 contains amplifier, bandpass, automaticgain control and sample and hold functions to enable programming orstoring of the recorded voice data. The voice stored may be of anylanguage to allow local language devices to be utilized, such as French,German, Italian, Spanish or English. This word list, or dictionary, maybe loaded and stored into programmer 10 analog memory 124 duringmanufacture and updated periodically via replaceable cartridges or vialoading software via diskettes, as is known in the art.

Turning now to FIG. 3, a flow diagram is shown which illustrates theprocess in accordance with the presently disclosed embodiment of theinvention. The flow diagram of FIG. 3 begins with a starting of theoperation of the programmer of block 200 by detection of data entry fromkeyboard 126 (or alternatively, mouse 128, track ball 130, or light pen132) or programmer function or status change. At block 202 the dataentry is monitored for programmer function request. At block 204 theflow diagram monitors for a warning or a telemetry response indicationrequested by microprocessor 108. If neither of these items areidentified the flow diagram returns to start block 200. If either ofthese items are valid, the microprocessor 108 in conjunction with theROM 122 and analog memory 124 assembles a word list at 206. When thelist is complete at block 208 the phrase or sentence is delivered toannunciator driver 106. Annunciator driver 106 drives the annunciator110 or speaker. At block 212 the last word in the phrase is tested for,if yes, the flow diagram stops at block 214. If no, it returns to block210 to continue reading the phrase.

Alternatively, a pacing systems analyzer may use the same analog memory124 under control of microprocessor 108 to announce pacing amplitude orpulse width changes during threshold measurements on a beat-by-beatbasis. Additionally, during intrinsic sensing measurements, the analyzermay announce R- or P-wave amplitudes on a beat-by-beat basis. Lastly,sensor signal characteristic amplitudes, widths or counts may beannounced.

From the foregoing detailed descriptions of the particular embodimentsof the invention, it should be apparent that a programmer has beendisclosed which is provided with the capability of audio communicationof data to facilitate the implant and follow-up process. While theparticular embodiments of the present invention have been describedherein detailed, it is to be understood that various alterations,modifications, and substitutions can be made therein without departingfrom the spirit and scope of the present invention, as described in theclaims, which follow.

We claim:
 1. In an apparatus for programming implantable medicaldevices, said programming apparatus having a data entry means forreceiving and entering by operator manipulations, manifestationscontrolling operation of said medical device;(a) having a transmittermeans responsive to said manifestations entered via said data entrymeans for encoding and transmitting corresponding signals to saidmedical device; (b) having means for receiving said encoded andtransmitted status and diagnostic values from said medical device; (c)having a display means for displaying a representation of said statusand said diagnostic values; (d) having a programmable microprocessorhaving a memory with a plurality of executable programs stored therein,said microprocessor comprising means responsive to said manifestationsfrom said data entry means for providing corresponding signals to saidtransmitter means and means for activating said transmitter means totransmit the corresponding signals to said medical device wherebycharacteristics of said medical device may be selectively changed, saidmicroprocessor comprising means responsive to said status and diagnosticvalues from said receiving means for causing said values to be displayedon said display means; the improvement comprising:(i) audio means undercontrol of said microprocessor for reproducing acoustic signalsrepresenting said status and said diagnostic values.
 2. An apparatusrecited in claim 1 wherein said reproduced acoustic signals arecomprised of stored voice signals.
 3. An apparatus recited in claim 2,further comprising means for defining a voltage level indicative of saidstored voice signals;(a) memory means for storing said voltage level;(b) means for durable maintaining said voltage level; and (c) means forretrieving said voltage level.
 4. An apparatus recited in claim 3,wherein said voltage level comprises an analog voltage level.
 5. Anapparatus recited in claim 3, wherein said memory means compriseselectrically alterable read only memory.
 6. In an implantable medicaldevice system analyzer for verifying operation of a cardiac pacingsystem including a pacing lead and a cardiac pacemaker to be implanted,said analyzer having a data entry means for receiving and entering byoperator manipulations, manifestations controlling operation of saidanalyzer; having a display means for displaying a representation of saidoperation of said medical device system; having a pacing means forstimulating said pacing lead; having a sensing means for sensingintrinsic heart signals conducted on said pacing lead; and having meansfor programming microprocessor having a memory with a plurality ofexecutable programs stored therein, said microprocessor responsive tosaid manifestations from said data entry means and responsive to saidsensing means and for activating said pacing means wherebycharacteristics of said cardiac pacing system may be evaluated anddisplayed on said display means; the improvement comprising:(a) audiomeans under control of said microprocessor for reproducing acousticsignals representing said characteristic of said cardiac pacing system.7. An apparatus recited in claim 6 wherein said reproduced acousticsignals are comprised of stored voice signals.
 8. An apparatus recitedin claim 7, further comprising means for defining a voltage levelindicative of said stored voice signals;(a) memory means for storingsaid voltage level; (b) means for durable maintaining said voltagelevel; and (c) means for retrieving said voltage level.
 9. An apparatusrecited in claim 8, wherein said voltage level comprises an analogvoltage level.
 10. An apparatus recited in claim 8, wherein said memorymeans comprises electrically alterable read only memory.
 11. A method ofoperating a programmer to be use in conjunction with an implantablemedical device, said programmer being controlled by an operator andhaving capabilities of programming said medical device, receiving datarepresenting status of said medical device and receiving telemetryrepresenting diagnostic data from said medical device, said programmergenerating acoustic signals representative or said status of saiddiagnostic data, said method comprising:(a) storing programmer memorysignals indicative of said medical device status, said programmer statusand said diagnostic data; (b) transmitting encoded signals to saidmedical device; (c) receiving encoded signals from said medical deviceupon the request of said programmer via said encoded transmittedsignals; (d) assembling signals from said programmer memory; and (e)reproducing an audible manifestation of said assembled signals.
 12. Themethod of claim 11 wherein the step of transmitting encoded signals tosaid medical device comprises transmitting signals for modifying afunction of said medical device.
 13. The method of claim 11 wherein thestep of transmitting encoded signals to said medical device comprisestransmitting signals for requesting said telemetry data.
 14. The methodof claim 11 wherein the step of assembling signals is comprised ofassembling signals indicative of said status.
 15. The method of claim 11wherein the step of assembling signals is comprised of assemblingsignals indicative of said diagnostic data.
 16. The method of claim 11wherein the step of reproducing an audible manifestation of saidassembled signals is comprised of reproducing an audible manifestationindicative of said status.
 17. The method of claim 11 wherein the stepof reproducing an audible manifestation of said assembled signals iscomprised of reproducing an audible manifestation indicative of saiddiagnostic data.
 18. A method of operating an analyzer to be used inconjunction with a medical device implanted within a patient, saidanalyzer being controlled by an operator and having capabilities oftesting and measuring status of said medical device and simulation andsensing requirements of said medical device in said patient, saidanalyzer also generating acoustic signals representative of said statusor said measured data, said method comprising:(a) storing in analyzermemory signals indicative of said medical device status, said analyzerstatus and said measured data; (b) assembling signals indicative of saidstatus or said measured data from said analyzer memory; and (c)reproducing an audible representation of said assembled signalsindicative of said status or said measured data.
 19. The method of claim18 wherein the step of assembling signals from said analyzer memory iscomprised of assembling signals indicative of said status.
 20. Themethod of claim 18 wherein the step of assembling signals from saidanalyzer memory is comprised of assembling signals indicative of saidmeasured data.
 21. The method of claim 18 wherein the step ofreproducing an audible representation of said assembled signals iscomprised of reproducing an audible representation of assembled signalsindicative of said status.
 22. The method of claim 18 wherein the stepof reproducing an audible representation of said assembled signals iscomprised of reproducing an audible representation of assembled signalsindicative of said measured data.